Electric circuit breaker with auxiliary switch means



Sept. 5, 1967 K|ESEL ET AL 3,340,375

ELECTRIC CIRCUIT BREAKER WITH AUXILIARY SWITCH MEANS Filed Oct. "7, 1965INSULATION INVENTORS GEbRGE W. X15551. HENRY E. S. OWE/V A TTURNEYUnited States Patent 3,340,375 ELECTRIC CIRCUIT BREAKER WITH AUXILIARYSWITCH MEANS George W. Kiesel and Henry E. S. Owen, Unionville, Conn.,assignors to General Electric Company, a corporation of New York FiledOct. 7, 1965, Ser. No. 493,834 3 Claims. (Cl. 200153) ABSTRACT OF THEDISCLOSURE An electric circuit breaker assembly including a main housingcontaining a pair of separable contacts and a movable member that moveswith the contacts between open and closed circuit positions; anauxiliary switch is included within the main housing and includes itsown insulating casing and its own operating member movable between onand olf position and biasing means biasing the operating member to afirst one of these positions at all times; a pivoted actuating member ismounted fixedly With respect to the auxiliary switch housing, and secondbiasing means is provided acting on the actuating member and biasing itto a position in which it engages the operating member of the auxiliaryswitch and retains it in the position opposite to the aforesaid firstposition; the aforesaid movable member which moves with the separablecontacts of the circuit breaker engages the actuating member and movesit away from its normal position against the bias of the second biasingmeans, thereby permitting the first biasing means to move the operatingmember of the auxiliary switch to the said first position; the actuatingmember is free to move a substantial distance against the second biasingmeans beyond the point where the operating member of the auxiliaryswitch has been moved to its first position, thereby permitting agreater latitude of movement by the movable member of the circuitbreaker mechanism.

The present invention relates to electrical circuit breakers and moreparticularly to circuit breakers including auxiliary switch members foroperating auxiliary devices to provide remote indication or control inaccordance with the condition of the circuit breaker mechanism.

Generally, auxiliary switches desirably are incorporated within thecircuit breaker casing for actuation upon movement of the circuitbreaker mechanism to the open circuit (off) condition, or to the closedcircuit (on condition, depending upon the construction of the switch,and thereby to control a remote device or indicator. Auxiliary switchesmay be used to operate trip or bell alarms, which are special typeauxiliary switches incorporated within the circuit breaker casing andactuated upon movement of the circuit breaker mechanism to the trippedor automatically open position, such as in response to an overload orshort circuit condition in the circuit controlled by the circuitbreaker. Auxiliary switches may be used to operate accessory devicessuch as trip or bell alarms, indicating lights, relays, contactors, andother similar uses simultaneously with the operation of the breaker.These switches may also be used as electrical interlocks to actuate anemergency power supply. Auxiliary switches may be used in connectionwith other auxiliary devices commonly used .in association with circuitbreakers, such as undervoltage trip devices and remote trip devices.

Electric circuit breakers of the type referred to herein generallyinclude an insulated casing of molded synthetic plastic material, andare usually provided in two and three-pole forms. However the auxiliaryswitch of this invention may be used with a single pole circuit breakeras well. The insulating casing provides elongated, substantiallyisolated chambers corresponding in number to the number of poles. Thus atwo-pole breaker comprises an insulated casing having two side-by-sideelongated chambers and a three-pole breaker comprises an insulatingcasing having three side-by-side elongated chambers.

In the construction of such circuit breakers, it is conventionalpractice to provide in each of such chambers at least one relativelystationary contact and one relatively movable contact carried by apivotally supported contact arm. In addition, in one of such chambers,the major portion of an operating mechanism is disposed and arranged tooperate all of such contact arms between open and closed circuitpositions either (a) manually by means of an operating handle, or (b)automatically by means of a releasable member normally held by a latchmember which in turn is releasably held by a trip" device actuated inresponse to abnormal electrical conditions in the circuit control led bythe circuit breaker to release the latch member. The contact arms ofeach of theseveral chambers are included in the operating mechanism ofthe circuit breaker.

Because of the presence of the major portion of the opera-ting mechanismin one pole chamber of the circuit breaker in addition to to thecontacts and contact arm, the room available therein for auxiliaryswitches or other devices is extremely limited. Therefore, auxiliarydevices such as auxiliary switches, trip alarms, undervoltage tripdevices, and remote trip devices have, because of their size andconstruction, necessarily been located only in the pole chambers of suchbreakers other than that occupied by the major portion of the operatingmechanism. The number and combination of such auxiliary devices whichcan be used in such breakers according to conventional practice isextremely limited. For example, if it is desired to utilize an auxiliaryswitch and a trip alarm device in a three-pole breaker, both chambersnot occupied by the operating mechanism would have to be utilized. Thisrenders it very ditficult to provide in the same breaker, anundervoltage trip device or remote trip device without increasing thesize or other major reconstruction. Similarly, when any one of theabove-mentioned auxiliary devices is incorporated in a two-pole circuitbreaker in accordance with conventional practice, the one available polechamber must be utilized and no other auxiliary device can be providedconveniently within the same circuit breaker.

It is an object of this invention to provide a novel auxiliary switchfor use in association with an electrical circuit breaker which isextremely compact. and efiective.

It is also an object of this invention to provide such a novel auxiliaryswitch which comprises a plurality of switches for operating accessoriessuch as indicating lights, relays and the like to indicate the conditionof the circuit breaker.

Another object is to provide such an auxiliary switch in the form of atrip alarm which can be mounted in the same pole chamber as thatoccupied by the main operating mechanism of the circuit breaker.

A further object is to provide such as auxiliary switch which enablesactuation of relatively delicate switch components by the relativelypowerful operating mechanism of the circuit breaker while substantiallyavoiding injury thereto.

It has now been found that the foregoing objects and other advantagescan be readily attained in an auxiliary switch for use with anelectrical circuit breaker comprises a support member for mounting on anassociated circuit breaker and a switch member for mounting on thesupport member for operating an accessory device by movement of anelement therein between open and closed position. An operating member ismovably mounted on the switch member for positioning the switch memberin open and closed circuit positions. An actuating member is pivotablymounted on the support member and engages the operating member uponpivoting thereof to move the operating member and actuate the switchmember from one circuit position to the other circuit position. Theactuating member has means engageable by the operating mechanism of theassociated circuit breaker for pivotal movement thereof away from theoperating member. A spring means is operable between the support memberand the actuating member and normally biases the actuating member aboutthe pivotal mounting in the direction of the operating member.

In accordance with one embodiment of this invention, the auxiliaryswitch is a trip alarm supported in the same pole section as the maincircuit breaker operating mechanism, and the pivotable actuating memberincludes a part projecting into the path of the releasable or trippingmember of the circuit breaker mechanism so as to be operated upontripping of the circuit breaker.

The auxiliary switches may include one to four or more normally open ornormally closed switches. A normally open switch is off when the circuitbreaker is in the open or tripped condition, and closed when the circuitbreaker is in the closed condition. A normally closed switch is closedwhen the circuit breaker is in the open or tripped condition and openwhen the circuit breaker is closed. A single auxiliary switch may beconstructed to operate either as a normally open or a normally closedswitch depending upon the leads from the switch that are used. Thus, anauxiliary switch may be selected that will either open a pair ofcontacts to deenergize a circuit when engaged by the actuating member orclose a pair of contacts and energize a circuit when engaged by theactuating member. Accordingly, various auxiliary switches may beselected and used in combination according to the purpose of theauxiliary device to which they are individually connected and whether itis desired to have the device energized or deenergized upon the openingor tripping of the circuit breaker mechanism.

In accordance with the present invention, the auxiliary switch providesan actuating member which enables the operation of relatively delicateswitch components in the switch member by the relatively hard drivingoperating mechanism of the circuit breaker without substantiallikelihood of injury thereto.

The invention will be more fully understood from the following detaileddescription and the scope will be pointed out in the appended claims.

In the drawings:

FIGURE 1 is a side elevational view of an electrical circuit breakerassembly incorporating the present invention with a portion of the sidewall of the insulating casing thereof being broken away for clarity ofillustration and showing the circuit breaker operating elements in theon condition;

FIGURE 2 is a side elevational view to an enlarged scale of the internalelements of the circuit breaker assembly of FIGURE 1 showing the circuitbreaker operating elements in the off position and parts of theauxiliary switch in phantom line;

FIGURE 3 is a side elevational view to an enlarged scale of a portion ofthe circuit breaker of FIGURE 1 with the operating parts of theauxiliary switch being shown in phantom line; and

FIGURE 4 is a front elevational view to an enlarged scale of theauxiliary switch of FIGURE 1 with portions thereof in section.

Referring now in detail to the drawings, the invention is shown inassembly with an electrical circuit breaker designated by the numeral 10which has a generally rectangular insulating casing with a base portion12 and a removable cover portion 14. For convenience, the constructionof a single pole chamber of the circuit breaker 10 is shown and will bedescribed in detail although it will be understood, however, that thecircuit breaker 10 generally includes three or more pole chambers, allsubstantially identical except that the center pole chamber contains themajor portion of the operating mechanism. Each pole chamber includes arelatively stationary contact (not shown) and a relatively movablecontact (not shown), carried by a contact arm 16 pivotably supported bya shaft 18 which is mounted on the base 12. The contact arm 16 islimited in movement about the shaft 18 by a stop 19 mounted on the base12.

In accordance with conventional construction, the movable contacts (notshown) are electrically connected to a trip unit 20 which is in turnelectrically connected to a load terminal (not shown) and the stationarycontacts are electrically connected to a line terminal (not shown). Theelectric circuit through each pole may therefore be traced as follows:from the line terminal to the stationary contact, and, when the circuitbreaker is in the closed position, through the relatively movablecontact to the trip unit, and then finally to the load terminal.

For the purpose of operating the contact arm 16 and its movable contactto open and closed circuit position, a suitable operating mechanism(only partially shown) is provided and has pivotably mounted operatinghandle 22 projecting the top wall of the circuit breaker cover 14. Threemovable contact arms 16 of the three-pole section are ganged togetherfor movement by the operating mechanism as a unit by means of thecross-bar 24 which is rigidly attached to each of the arms 16. Theoperating mechanism may, for example, be as shown in United StatesPatent No. 2,921,169 issued Jan. 12, 1960, to E. B. Judd and J. D.Young, and assigned to the same assignee as the present invention.

For the purpose of providing a plurality of auxiliary switching means,which shall be in one condition when the circuit breaker is in the offposition and another condition when the circuit breaker is in the onposition, the circuit breaker assembly incorporates an auxiliary switchincluding a sheet metal support bracket or member generally designatedby the numeral 26 with a generally flat, plate-like body portion 28 anda bent-over flat end portion 30 which abuts against the trip unit 20 andis secured thereto by means of bolts 32 disposed in apertures 33. On theopposite end of the body portion 28, another bent-over flat portion 34is engaged by rivets 38 with an insulating support 37 which is keyedinto and supported by slots (not shown) in the base 12 of the circuitbreaker 10. A depending flange portion 44 on the body portion 28pivotally supports a generally L-shaped switch actuating membergenerally designated by the numeral 46 by means of the pivot pin 48which is disposed in an aperture (not shown) in the central portion ofthe actuating member 46. The L-shaped actuating member 46 has two legportions 47 and 49 which extend to opposite sides of the pivot pin 48. Ahelical tension spring 50 is hooked in the aperture 52 in the legportion 47 of actuating member 46 and in the aperture 54 in the bodyportion 28 of the support bracket 26. A bent-over flange portion 56 onthe leg portion 49 provides a surface area for engagement with thecross-bar 24 of the contact arm 16.

A plurality of miniature push-button actuated switch FIGURE 4. Each ofthe miniature switch members 60 are connected together and attached tothe bracket sup port 26 by means of bolts 62. The switch members 60 areeach separated by insulating members 63 as best seen in FIGURE 4. Eachof the miniature switch members 60 comprises an insulating casing 64, astationary contact 66 mounted On a conducting support member 68 mountedOn the insulating casing 64, and a movable contact memher or switchelement 70 movably supported in the casing 64 by means of a resilientlydeflectable connecting support member 72 which acts as a leaf springbiasing the movable contact 70 into engagement with the stationarycontact 66. The resiliently deflectable support member 72 is adapted tobe operated by a rectilinearly moving pushbutton operating member 74which is slidably seated in the casing 64 and projects outwardlythereof. The construction and arrangement of the miniature switchmembers 60 are such that, in the absence of any actuating force on theoperating member 74, the resiliently deflectable support member 72biases the movable contact 70 into engagement with the stationarycontact 66. However, it will be obvious that the resiliently deflectablesupport member 72 may be arranged so that it normally biases the movablecontact 70 away from the stationary contact 66 so that the contacts 66and 70 are only engaged when the operating member 74 moves the supportmember 72 toward the stationary contact 66.

An elongated switch operating arm 76 is supported on the flange 78 ofthe leg portion 47 of the actuating member 46 adjacent the tensionspring 50 which biases the actuating member 46 about the pivot pin 48 inthe direction of engagement with the operating members 74. The operatingarm 76 extends along the bottom portion of switch members 60 so that itmay substantially simultaneously engage all the operating members 74.

As shown in FIGURE 1, when the contact arm 16 and operating mechanism ofthe circuit breaker are moved to the on position, the cross arm 24 ismoved from engagement with flange portion 56 of the actuating member 46.In this condition, the actuating member 46 is biased about the pivot pin48 by the spring 50 into engagement with the operating members 74,whereby the operating members 74 are slidably moved to the positionillustrated in FIGURE 3. When the actuating member 46 is in the onposition, the operating member 74 is biased against the resilientlydeflectable support member 72 so that the movable contact 70 isdisengaged from the stationary contact 66. Accordingly, the switch 60 isin the open circuit position when the contact arm 16 and the operatingmechanism of the circuit breaker are in the closed circuit position.

When the operating mechanism of the circuit breaker is moved to the openposition as illustrated in FIGURE 2, the contact arm 16 is pivoted in acounterclockwise direction about the shaft 18 until it is restrainedfrom upward movement by the stop 19. The cross arm 24 is thus moved intoengagement with the flange 56 to rotate the actuating member 46 in aclockwise direction against the force of the tension spring 50, and theswitch operating arm 76 of the actuating member 46 is thus moved fromengagement with the operating member 74. The resiliently deflectablesupport member 72 biases the operating member 74 to the position shownin FIGURE 2 and the movable contact 70 is moved into electricalengagement with the stationary contact 66. Accordingly, the auxiliaryswitch 60 is in the closed circuit position when the contact arm 16 andthe operating mechanism of the circuit breaker are in the off or opencircuit position. An auxiliary device electrically connected through theauxiliary-switch 60 is thus activated when the stationary contact 66 andmovable contact 70 are electrically engaged when the circuit breaker isin the off position. Thus, a relatively fragile auxiliary switch 60 isoperable by the actuating member 46 without being in direct contact withthe cross-bar 24 of the relatively powerfully driven operating mechanismof the circuit breaker and the relatively large movements thereof. Alsoby providing the spring biased actuating member 46, the operating member74 which requires relatively small movements to activate switch 60, maybe operated by the relatively large movements of the circuit breakeroperating mechanism without damaging the relatively delicate auxiliaryswitch 60.

As previously indicated, the resiliently deflectable support member 72may be arranged so that it biases the movable contact 70 away fromengagement with the stationary contact 66 when the actuating member 46is in the off position shown in FIGURE 2. In such an arrangement, theauxiliary switch may be easily arranged so that the operating member 74biases the resiliently deflectable support member 72 into engagementwith the stationary contact 66 when the actuator 46 is in the onposition as shown in FIGURE 3, thus activating an auxiliary device whenthe circuit breaker is in the on condition.

It can be seen from the foregoing detailed description and drawings thatthe present invention provides an auxili-ary switch for use with acircuit breaker which is novel, effective and compact, and which may beused in combination for operating a plurality of accessory devices suchas to indicate the condition of the circuit breaker. The auxiliaryswitches may be selected so that they either open or close a circuitupon tripping or manually opening the circuit breaker, or to operate atrip alarm. The switches are sufliciently compact to be mounted in thesame pole chamber as that of the operating mechanism of the circuitbreaker and also provide for actuating relatively delicate switchcomponents upon tripping or opening of the relatively powerful circuitbreaker mechanism without damage thereto.

While we have disclosed only certain embodiments of the invention, itwill be readily appreciated that many modifications thereof may be made.We therefore intend by the appended claims to cover all suchmodifications as fall within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. An electric circuit breaker assembly comprising:

(a) an insulating casing;

(b) at least one pair of relatively separable contacts supported in saidcasing;

(c) operating mechanism in said insulating casing for moving saidcontacts between open and closed circuit positions;

(d) a movable member movably supported in said insulating casing, saidmovable member moving between first and second positions upon movementof said contacts between said open and closed circuit positionsrespectively;

(e) an auxiliary switch supported in said insulating casing, saidauxiliary switch comprising an insulating housing and an operatingmember carried by said insulating housing and movable between first andsecond positions to operate said switch between open and closed circuitconditions;

(f) first biasing means biasing said operating member for movementtoward said firstposition at all times;

(g) an actuating member pivotally supported on said insulating housingof said auxiliary switch member and movable between first and secondpositions, said actuating member when in said first position engagingand retaining said operating member in said second position against thebias of said first biasing means;

(h) second biasing means biasing said actuating member toward said firstposition at all times, said second biasing means exceeding said firstbiasing means whereby said actuating member normally engages saidoperating member and retains said operating member in said secondposition;

(i) said movable member engaging said actuating member when saidcontacts are in said open circuit position and moving said actuatingmember from said first toward said second position against the bias ofsaid second biasing means whereby said first biasing means is free tomove said auxiliary switch oper ating member to said first position.

2. An electirc circuit breaker assembly as set forth in 75 claim 1wherein said actuating member travels a sub- 7 stantial distance in thedirection from said first toward said second position after saidoperating mechanism is in said second position whereby travel of saidmovable member is substantially uninhibited by said actuating member.

3. An electric circuit interrupter assembly as set forth in claim 2wherein said circuit breaker assembly includes at least one pivotallymounted contact arm assembly and wherein said movable member comprises aportion of said pivotally mounted contact arm assembly.

8 References Cited UNITED STATES PATENTS 7/1954 Boller et a1 200-1674/1961 Piteo et al. 200-414 ROBERT S. MACON, Primary Examiner. ROBERT K.SCHAEFER, Examiner. H. BURKS, Assistant Examiner.

1. AN ELECTRIC CIRCUIT BREAKER ASSEMBLY COMPRISING: (A) AN INSULATINGCASING; (B) AT LEAST ONE PAIR OF RELATIVELY SEPARABLE CONTACTS SUPPORTEDIN SAID CASING; (C) OPERATING MECHANISM IN SAID INSULATING CASING FORMOVING SAID CONTACTS BETWEEN OPEN AND CLOSED CIRCUIT POSITIONS; (D) AMOVABLE MEMBER MOVABLY SUPPORTED IN SAID INSULATING CASING, SAID MOVABLEMEMBER MOVING BETWEEN FIRST AND SECOND POSITIONS UPON MOVEMENT OF SAIDCONTACTS BETWEEN SAID OPEN AND CLOSED CIRCUIT POSITIONS RESPECTIVELY;(E) IN AUXILIARY SWITCH SUPPORTED IN SAID INSULATING CASING, SAIDAUXILIARY SWITCH COMPRISING AN INSULATING HOUSING AND AN OPERATINGMEMBER CARRIED BY SAID INSULATING HOUSING AND MOVABLE BETWEEN FIRST ANDSECOND POSITIONS TO OPERATE SAID SWITCH BETWEEN OPEN AND CLOSED CIRCUITCONDITIONS; (F) FIRST BIASING MEANS BIASING SAID OPERATING MEMBER FORMOVEMENT TOWARD SAID FIRST POSITION AT ALL TIMES; (G) AN ACTUATINGMEMBER PIVOTALLY SUPPORTED ON SAID INSULATING HOUSING OF SAID AUXILIARYSWITCH MEMBER